Employee Retirement Plans - Summary of the Basis Used to Measure Pension Plans' Assets at Fair Value (Details) (USD $) In Thousands, unless otherwise specified	Dec. 29, 2012		Dec. 31, 2011	Dec. 31, 2010
Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 3,503		$ 3,188	$ 3,342
Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	8,781		7,820	8,253
Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	12,997		11,518	0
Total [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	3,503
Total [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	8,781
Total [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	12,997
Total [Member] | Short Term Investment Fund [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	205	[1]
Total [Member] | Short Term Investment Fund [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	402	[1]
Total [Member] | Short Term Investment Fund [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	328	[1]
Total [Member] | Equity Securities [Member] | Elgin Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	752
Total [Member] | Equity Securities [Member] | Elgin Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	86
Total [Member] | Equity Securities [Member] | Elgin Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	84
Total [Member] | Equity Securities [Member] | Elgin Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	778
Total [Member] | Equity Securities [Member] | Smithville Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,920
Total [Member] | Equity Securities [Member] | Smithville Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	223
Total [Member] | Equity Securities [Member] | Smithville Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	212
Total [Member] | Equity Securities [Member] | Smithville Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,958
Total [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Developed Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	3,663
Total [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	548
Total [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Global Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	636
Total [Member] | Equity Securities [Member] | Wrexham Plan [Member] | United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	4,430
Total [Member] | Fixed Income [Member] | Elgin Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,119
Total [Member] | Fixed Income [Member] | Elgin Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	141
Total [Member] | Fixed Income [Member] | Smithville Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,861
Total [Member] | Fixed Income [Member] | Smithville Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	353
Total [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,965
Total [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Aggregate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	373
Total [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Index Linked [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,054
Total [Member] | Alternative [Member] | Elgin Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	139
Total [Member] | Alternative [Member] | Elgin Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	199
Total [Member] | Alternative [Member] | Smithville Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	355
Total [Member] | Alternative [Member] | Smithville Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	497
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	3,298
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	8,379
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	12,669
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Short Term Investment Fund [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	[1]
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Short Term Investment Fund [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	[1]
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Short Term Investment Fund [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	[1]
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	752
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	86
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	84
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Elgin Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	778
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,920
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	223
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	212
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Smithville Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,958
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Developed Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	3,663
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	548
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Global Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	636
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	4,430
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Elgin Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,119
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Elgin Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	141
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Smithville Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	2,861
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Smithville Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	353
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,965
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Aggregate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	373
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Index Linked [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	1,054
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Alternative [Member] | Elgin Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	139
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Alternative [Member] | Elgin Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	199
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Alternative [Member] | Smithville Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	355
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Alternative [Member] | Smithville Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	497
Significant Observable Inputs (Level 2) [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	205
Significant Observable Inputs (Level 2) [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	402
Significant Observable Inputs (Level 2) [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	328
Significant Observable Inputs (Level 2) [Member] | Short Term Investment Fund [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	205	[1]
Significant Observable Inputs (Level 2) [Member] | Short Term Investment Fund [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	402	[1]
Significant Observable Inputs (Level 2) [Member] | Short Term Investment Fund [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	328	[1]
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Elgin Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Smithville Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Developed Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Global Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Elgin Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Elgin Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Smithville Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Smithville Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Aggregate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Index Linked [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Alternative [Member] | Elgin Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Alternative [Member] | Elgin Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Alternative [Member] | Smithville Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Observable Inputs (Level 2) [Member] | Alternative [Member] | Smithville Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Short Term Investment Fund [Member] | Elgin Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	[1]
Significant Unobservable Inputs (Level 3) [Member] | Short Term Investment Fund [Member] | Smithville Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	[1]
Significant Unobservable Inputs (Level 3) [Member] | Short Term Investment Fund [Member] | Wrexham Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0	[1]
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Elgin Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Elgin Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Mid Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Smithville Plan [Member] | Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Smithville Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Developed Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | International Global Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] | Wrexham Plan [Member] | United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Elgin Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Elgin Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Smithville Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Smithville Plan [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Government/Corporate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Aggregate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Fixed Income [Member] | Wrexham Plan [Member] | Index Linked [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Alternative [Member] | Elgin Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Alternative [Member] | Elgin Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Alternative [Member] | Smithville Plan [Member] | Global Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	0
Significant Unobservable Inputs (Level 3) [Member] | Alternative [Member] | Smithville Plan [Member] | Commodities Investment [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of pension plan assets	$ 0

[1] Represents collective short term investment fund, composed of high-grade money market instruments with short maturities.